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Full text of "The Morphology And Evolution Of The Apes And Man"

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THE XERVOUS  SYSTEM                  -#7
2.  Pharyngeal nerve  a-.
3.  Superior laryngea! nerve ib .
(i) External laryngeal nerve, (ii) Internal laryngeal nerve.
4.  Eight recurrent nerve.
5.  Cardiac branch of left vagus  f..
6.   To cardiac and trachea! plexus of right vau'r-.
The thoracic parts of the vagi have the same course a> in Man. In the Chimpanzee they do not break :^p :r;ie posterior pulmonary plexuses as they Jo in the Orang and Man. Their branches are shown in the t?K:.wIs^ table. Their arrangement in the Chimpanzee :-. sh<"vn in fig. 53.
Left Vagus.
1.  Eecurrent nerve ie*.
2.  Cardiac nerve <f).
3.  Anterior pulmonary nerves.
4.  Posterior pulmonary nerves.
5.  CEsophageal nerves.
6.   Communicating to right vagus.
Bight Vagus.
1.  Three cardiac nerves if,'.
2.  Three anterior pulmonary nerves *gK
3.  Tracheal branches <T.BA
4.  Two posterior pulmonary nerves -h>.
5.  QEsophageal nerves.
In the Orang the vagi fuse below the pulmonary roots* The abdominal parts of the vagus nerves are extensive. In the Chimpanzee the left vagus passes through the anterior part of the cesophageal opening in the stomach and runs along the lesser curvature of the stomach, supplying it and the oesophagus and communicating with the right vagus. The latter ends in the left semilunar ganglion: it gives off cesophageal (O.K.) and gastric